Lights in several rooms don't work

[tommyb]

Hi,

The lights in three rooms on my house have stopped working. My daughter said they went out when she switched the lights off last night in one of the rooms. I've checked the fuse box and all those for lights are OK. The bulbs in each room are fine. The three rooms affected are in a row at the front of the house and all other rooms are unaffected.

Can anyone give me any pointers to check?

Thanks.

Tommy.

 

[JohnD]

lighting circuits are generally connected in a row like beads on a necklace (not in a ring).

You probably have a bad connection at one of the "beads".

This is most likely at the ceiling rose where the cable "in" from the previous lamp is joined to the cable "out" to the next lamp.

It will be either at the first lamp that does not work; or the preceding one that does.

Turn off the power, get a test meter (preferably not a neon screwdriver but one of these http://www.doctronics.co.uk/images/meter2.gif ) that will cost about £8 in the high street) and your stepladder; unscrew the cover of the ceiling rose, and examine the terminals for tightness or loose wires.

Try not to take any wires out of any terminals. If you do, it is absolutely essential that you mark each wire so that it can be put back into the same terminal. There will be several wires of the same colour fulfilling different purposes and if you mix them up the job will be twenty times as difficult for you.

Only work on one rose at a time and test the lights after each one. If you disturb two you will not know which caused any effects that occur.

You will use the meter to fault-find if you cannot fix the problem by finding and tightening a loose connection. I will talk you through that if necessary. You should find all the wires are insulated in shiny PVC. If you find any that are in rubber, especially if it is old, cracked or perished; or if you find signs of overheating, please come back and describe what you found.

There are helpful diagram of lighting circuits - go to "Electrics UK" then "Wiki: Please see if the answer to your query is aleady covered by the Wiki" and "Sticky: Read Here First - FAQ - For reference"

 

[tommyb]

Thanks JohnD. I'll give it a look.

 

[tommyb]

JohnD,

I completely forgot to mention that one of the rooms is being wallpapered and the light switches and wall lights are loosened from the wall Perhaps there's a loose wire there somewhere.

One question ... I checked the main dimmer switch (which has a dimmer for the main room light and a dimmer for the wall lights) to see if it had loose wires and there's two sealed 'boxes' marked "N4002 Tungsten Dimmer". The wires into and out of these are tight but is it possible or likely that there's something gone in the sealed dimmer boxes?

Tom.

 

[JohnD]

If the lights are out in several rooms, it won't be the switch (assuming it just has a red, a black and an earth wire going to it).

If, in the room you are decorating, you have disturbed the ceiling rose, that is probably the one. If the wall lights are wired as if they were ceiling roses (look at the diagrams I mentioned before) that could well be the trouble. Wall lights may have been added with a junction box hidden somewhere, that could be loose.

If you have put drills or nails through the ceiling or walls, you may have damaged a cable.

 

[tommyb]

Thanks.

>If, in the room you are decorating, you have disturbed the ceiling rose, >that is probably the one.

Or possibly a wall light?

>If you have put drills or nails through the ceiling or walls, you may have damaged a cable.

No drilling or nailing done, thank goodness

I'm wondering why all the lights went out suddenly, as they were all working OK and nothing had been changed. My daughter was in the room being decoarted, switched the lghts off on the way out and the lights in the other rooms went out too. Is there likely to be any other fuses somewhere other than the main fusebox?

Tom.

 

[JohnD]

Is there likely to be any other fuses somewhere other than the main fusebox?

Almost certainly not. It is much more likely that there is a loose connection, which failed when there was a current surge at light switch on/off.

As Softus often says, it is in the nature of faults to be sudden. One minute things work, the next they don't.

 

[tommyb]

OK - thanks - I'll let you know how I get on

Tom.

 

[tommyb]

Now sorted - after checking all the wires were OK today, I noticed tonight that the outside light wasn't working either .... in the fuse box there was a fuse marked 'outside light' (which I hadn't checked previously) and when I replaced it, bingo - all working! Looks like the spark took a short-cut in wiring or in naming the fuses

Thx for your help anyway.

Tom.

 

[securespark]

For future reference for others reading this in the future, occasionally you find two live wires in a switch box. If these are broken, some lights extinguish.